Gene Transcripts in the Tumor Suppressor Region of Chromosome 3 (3p21)

Background:There is increasing evidence that the short arm of chromosome 3 has a tumour suppressor region that has been associated with permanent growth arrest of tumour cells. We have identified 9 closely related genes in this region (CCDC12, KLH9, KLH18, MYL3, NBEAL2, PTPN23, SCAP, SETD2, and TESSP2) located which could be possible candidates for tumour suppressor genes (TSG).Our objective was to determine, using quantitative PCR, whether the mRNA expression levels of these genes were consistent with a tumour suppressive function in human breast cancer.Methods:A total of 153 samples were analysed. The levels of transcription of all 9 genes were determined using quantitative PCR and normalized against (CK19).Transcript levels within breast cancer specimens were compared with non-cancerous breast tissue and analyzed against conventional pathological parameters and clinical outcome over a 10 year follow-up period.Results:Quantification of CCDC12, KLH9, KLH18, MYL3, NBEAL2, PTPN23, and SCAP mRNA expression after CK19 normalisation showed no statistically significant difference between malignant and normal breast tissue (p=0.23, 0.46, 0.3, 0.141, 0.8, 0.696, and 0.11 respectively). The mRNA expression of TESSP2 was higher in normal samples compared with malignant lesions (347 vs. 35, p=0.0061) but showed no significant associations with clinical outcome.The levels of SETD2 mRNA were significantly lower in malignant samples (406 vs. 17, p=0.0345) and decreased with increasing tumour stage. SETD2 expression levels were significantly lower in samples from patients who developed metastasis, local recurrence, or died from breast cancer when compared to those who were disease free for > 10 years (p=0.041).Conclusion:These findings are consistent with a possible tumour suppressor function of SETD2 in human breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6139.

Transforming Acidic Coiled-Coil-Containing Protein 2 (TACC2) in Human Breast Cancer, Expression Pattern and Clinical/Prognostic Relevance

BACKGROUND: TACC2 is a member of the transforming acidic coiled-coil-containing protein family and is associated with the centrosome-spindle apparatus during cell cycling. In vivo, the TACC2 gene is expressed in various splice forms predominantly in postmitotic tissues, including heart, muscle, kidney, and brain. Recent work has shown that members of this family, including TACC2, may be involved in the progression of certain solid tumours. The aim of the current study was to identify the role of TACC2 in breast cancer and to establish if a prognostic relevance exists.MATERIALS AND METHODS: Fresh frozen primary human breast cancer tissues (n = 120) and non-neoplastic mammary tissues (n = 32) were used. The distribution and location of TACC2 was assessed using immunohistochemical staining (IHC) and imaging analysis tools. The transcript levels of TACC2 were determined using quantitative real time-PCR. The results were analyzed against the clinical, pathological and follow-up (10 years) data. Statistical analysis was by Mann-Whitney U test and Kaplan-Meier method. Shown are median transcript level.RESULTS: TACC2 protein staining was seen in both normal epithelial cells and cancer cells in mammary tissues. Increased staining of TACC2 was seen in most of the breast tumours examined when compared with normal breast tissues. Quantitative analysis of the TACC2 transcript also revealed a higher level expression in tumours compared with normal tissues (p=0.027, tumours vs normal). TACC2 expression was significantly increased in higher grade tumours compared to those in lower grade tumours (grade-3 vs grade-1, p=0.046). Using the Nottingham Prognostic Index (NPI), TACC2 transcript was significantly higher in tumours from patients with a moderate prognosis than from those with a good prognosis (p = 0.019). The expression in samples from patients with poor clinical outcome (with metastasis, recurrence and breast cancer related death) was significantly higher than that from patients who remained disease free (median (IQR) 33.8 (3.0-110.2) copies vs 6 (1.6-28.9) copies, p=0.038). This was reflected by the shorter disease-free survival for patients with high TACC2 (107 (91-122.8, 95% CI) months compared with 137 (125-150.6) months for patients with low TACC2 transcripts (p=0.019).CONCLUSION: This study shows that increased expression of TACC2 correlates with poor prognosis in patients with breast cancer. This suggests that TACC2 mediates an oncogenic effect on breast cancer cells. The findings also suggest that TACC2 may be a potential therapeutic target.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3159.

Suppressors of Cytokine Signaling and Their Role in Human Breast Cancer

BACKGROUND:Suppressors of cytokine signaling (SOCS) are important negative feedback regulators of the JAK/STAT signaling pathway, and have been recently investigated for their role in the development of different cancers. In this study, we examined the expression of SOCS 1-7 genes in normal and breast cancer tissue and correlated this with several clinico-pathological and prognostic factors.PATIENTS AND METHODS:SOCS 1-7 mRNA extraction and reverse transcription were performed on breast cancer tissue samples (n= 127) and normal background breast tissue (n= 31). Transcript levels of expression were determined using real-time PCR and analyzed against TNM stage, tumour grade and clinical outcome over a 10 year follow-up period.RESULTS:SOCS 1,4,5,6 and 7 expression decreased with increased TNM stage (TNM1 vs. TNM3 p= 0.039, TNM1 vs. TNM4 p= 0.016, TNM1 vs. TNM3 p= 0.012 and TNM1 vs. TNM3 p= 0.044 respectively). SOCS 2 and 3 expression decreased with increased Nottingham Prognostic Index (NPI) (NPI1 vs. NPI3 p=0.033 and NPI2 vs. NPI3 p=0.041 respectively). SOCS-7 expression decreased with higher tumour grade (Grade 3 vs. Grade 2 p=0.037). After a median follow up period of 10 years, we found higher levels of SOCS 1, 2 and 7 expression among those patients who remained disease-free compared to those who developed local recurrence (p= 0.0073, p= 0.021 and p= 0.039 respectively). Similarly, we found higher levels of SOCS 2, 4 and 7 expression in those who remained disease-free compared to those who developed distant recurrence (p= 0.022, p=0.024 and p= 0.033 respectively). Patients who remained disease-free had higher levels of SOCS 1 and 2 expression compared to those who died from breast cancer (p= 0.02 and p=0.033 respectively). The disease free survival (DFS) and overall survival (OS) curves showed that higher levels of SOCS 1, 3 and 7 were significant predictors of higher DFS (p=0.015, p=0.024 and p=0.03 respectively) and OS (p=0.005, p=0.013 and p= 0.035 respectively). Higher levels of SOCS 4 were significant in predicting better OS (p=0.007) but not DFS.CONCLUSIONHigher mRNA expression levels of SOCS 1, 3, 4 and 7 are significantly associated with earlier tumour stage and better clinical outcomes in human breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3157.

Impact of IL17B on Endothelial Cells and Angiogenesis

Introduction:Tumour angiogenesis plays a vital role in cancer development and spread. In the current study, IL17B was found to be unregulated in endothelial cells in response to Hepatocyte Growth Factor (HGF). IL17B shares structural similarities to IL17A, which has been previously proposed to promote angiogenesis and tumourgenicity, though currently the role of this cytokine in cancer or angiogenesis is largely unknown.Methods:HECV gene expression in response to HGF treatment was examined over a wide range of genes using micro array analysis to detect differential gene expression over the U133+2 chip. Recombinant human IL17B (rhIL17B) was subsequently used to treat human HECV endothelial cells over a range of concentrations. The impact of rhIL17B on HECV cell motility and angiogenic potential was assessed using Matrigel migration/wounding and tubule formation.Results:Micro array analysis detected a significant increase in IL17B expression in response to 4 hour treatment of HECV human endothelial cells with 40ng/ml HGF (p < 0.05 vs HGF untreated HECV cells). rhIL17B negatively influenced HECV tubule formation at the higher concentrations with substantial reduction in tubule formation being seen following treatment with 250ng/ml rhIL17B. Higher concentrations of rhIL17B were also seen to reduce the capacity of HECV cells to migrate in a scratch wounding assay and significant differences in migrated distance were observed following 75 minute incubation (P < 0.05 vs control untreatment group).Conclusions:Micro array analysis suggests that IL17B gene expression in the HECV human endothelial cell line can be upregulated in response to treatment with HGF. Subsequently high levels of rhIL17B were seen to negatively impact on the tubule formation and migratory capacity of this cell line. Together this data suggests that IL17B is unlikely to play a key role in the pro-angiogenic response initiated through HGF signalling but at higher concentrations may itself be able to negatively impact the angiogenic potential of the HECV endothelial cell line.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2157.

Prognostic Significance of Placenta Growth Factor (PlGF)-1 and PGF-2 Expression in Human Breast Cancer

Background: Placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGf) family, a group of angiogenic growth factors important in cancer development. Over-expression of PlGF is known to be associated with pathological angiogenesis. Recently, PlGF has been shown to have 4 isoforms, -1, -2, -3 and -4. This current study examined the expression of PlGF-1 and -2 in human breast cancer and how changes in expression of these isoforms may be linked to prognosis of the disease.Materials and Methods: Breast cancer primary tumours (n=114) and matched background tissue (n=30) were processed for RNA extraction. RNA was reversed transcribed and quantified before analysis by Q-PCR. The results were expressed as copy number of transcript/50ng RNA and standardised using β-actin. Statistical analysis was carried out using student t test (mean±SD) and Mann-Whitney U test (median/IQR) where appropriate. Immunohistochemistry was also carried out on a number of matched background and tumour sections.Results: Analysis of patients with a 10 year follow-up showed that transcript levels of PlGF-1 were increased in node positive tumours when compared to node negative (104.2±52.2 versus 52.5±13.6, respectively, but this did not reach significance(p=0.34). Prognostic indicators (NPI status, TNM status and grade of tumour) were not associated with significant changes in levels of PlGF-1. Moreover, there was no difference in expression with overall ER status of tumours; however, PlGF-1 was significantly increased in ERβ positive tumours (median values ERβ-ive and ERβ+ive (14.10 vs 68.75 respectively, p=0.014). Most interestingly, there was a significant increase in PlGF-1 expression in patients with poor outcome (median values patients remaining disease-free 16.5, patients who died from breast cancer 78.2, p=0.03). In comparison, the PGF-2 isoform showed little change in expression between tumour and background samples. However, Immunohistochemistry demonstrated a marked increased in PGF-2 expression in tumour sections (staining intensity (mean±SD): Background 102.05± 46.65 vs Tumour 172.85±40.33, n=20, p=0.0001).Conclusions: We can conclude from this data that there is a differential expression of the PlGF isoforms in human breast cancer. Inappropriate expression of PlGF isoforms may play a role in human breast cancer progression.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3041.

Evaluation of the Distribution of Stem Cell Markers in Human Breast Cancer Reveals Correlation with Clinical Progression and Metastatic Disease in Ductal Carcinoma

Background: Tumour stem cell theory suggests that a small percentage of cells in a tumour harbour intrinsic characteristics making them resistant to treatment. This could explain how patients with metastatic disease show clinical relapse several months after starting treatment due to the survival of a small group of cells with unique characteristics, including the ability to give rise to a new population of cells with resistant phenotype. We examined the distribution and expression of a panel of stem cell markers in human breast cancer primary tumours.Methods: Breast cancer primary tumours (n=114) and matched background tissue (n=30) were processed for frozen sections and RNA extraction. Frozen sections from matched tissues (tumour and background) were immuno-stained with PSCA, CD44, CD49b and CD133 antibodies and staining intensity analysed by computer image analysis. RNA was reverse transcribed and quantified before analysis by Q-PCR for the stem cell markers. Results were expressed as copy numbers of transcript/50 ng RNA (standardised by GAPDH/CK19).Results: Immunohistochemical assay revealed that there was a loss of expression of PSCA in tumour sections (149.85±24.89) compared to background tissue (222.85±9.88, n=20, p<0.0001). CD44 protein was expressed strongly in background endothelia and epithelia but was weaker and diffuse in tumour cells (134.5±29.89 and 187.9±21.28 respectively, p<0.0001). CD133 expression was lost in tumour-associated endothelial cells with diffuse and weak staining in tumours compared to background (194.9±35.76 and 222.2±20.46 respectively, p<0.006). Conversely, CD49b strongly stained in tumour and associated vessels and ducts but was weakly stained in background epithelia, albeit strongly staining background ducts and vessels (166.7±29.78 and 211.75±15.32 respectively, p<0.0001). Quantitative analysis of the gene transcripts further illuminated the expression of the stem cell markers: CD44 and PSCA were reduced in patients with poor outcome (metastatic disease and death from breast cancer), with a marked reduction in ductal carcinoma, particularly with metastasis to bone although these did not reach significant difference. However, CD49b and CD133 were significantly reduced in patients with metastatic disease (0.0001±0.0002 and 3.63±3.4 respectively) compared with those remaining alive and well after 10 year follow-up (31±15, p=0.03 and 553±261, p=0.039). CD133 was also significantly reduced in patients with ductal carcinoma/bone metastasis. Conversely, CD49F was increased in patients with a poor outcome and those with ductal cancer and bone metastases.Conclusion: This is the first study to determine the distribution and expression pattern of these stem cell markers in human breast cancer. We have shown that there is a significant association between loss of expression and metastatic disease in patients with breast cancer. Such differential expression may play a part in breast cancer disease progression, and suggests that the current stem cell theory may not hold true for all cancer types.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1157.

The Role of ALCAM, Activated Leukocyte Cell Adhesion Molecule, in the Aggressive Nature of Breast Cancer Cells, a Potential Connection to Bone Metastasis

Introduction. ALCAM, activated leukocyte cell adhesion molecule, has been previously reported to be connected to the progression of certain solid tumours. In breast cancer, ALCAM has been shown to be expressed at a reduced level in aggressive tumours (King et al 2004) and is a prominent feature for tumours subsequently developed bone metastasis (Davies et al 2008). In the present study, we investigate the molecular impact of ALCAM on the biological behaviours of breast cancer cells with a particular reference to condition that is linked to bone biological environment.Methods. A mammalian ALCAM expression construct was prepared from normal mammary cDNA bank using a pEF6.V5/His vector. Anti-ALCAM transgenes were prepared based on human ALCAM mRNA structure and cloned into a mammalian expression vector. Suitable cells were transfected with either the expression construct or anti-ALCAM transgene, to create sublines that had differential expression of ALCAM. The growth, migration and invasion of the aforementioned cells, together with their parent and control cell lines were evaluated using a panel of in vitro cell models, in the presence or absence of matrix proteins prepared from human bones. Statistical analysis was Student t test or Mann-Whitney test, where appropriate.Results. Of the 12 human breast cancer lines tested, ZR-75-1 was found to be strongly positive for ALCAM expression, whereas MDA-MB-231 was negative. ZR-75-1 was therefore transfected with the anti-ALCAM transgene. After selection, a subline, ZR-751ΔALCAM was created in which ALCAM expression was knocked out. Likewise, MDA-MB-231 was transfected with ALCAM expression construct, followed by creation of new subline, MDA-MB-231ALCAMexp, a sublined that over-expressed ALCAM. MDA-MB-231ALCAMexp cells showed a marginally slower rate of growth compared with control cells. However, in the presence of bone matrix proteins, MDA-MB-231ALCAMexp showed a significantly reduced rate of growth (growth index 0.62±0.11), p<0.01 vs control cells (1.06±0.15). In contrast, ZR-751ΔALCAM cells showed a faster pace of growth (1.04±0.14) compared with control cells (0.81±0.09). In an extracellular matrix based in vitro invasion assay, it was observed that MDA-MB-231ALCAMexp displayed a significantly reduced invasiveness compared with control cells (p=0.012). ZR-751ΔALCAM cells showed a significantly increased invasiveness vs its control cells (p=0.02). In an electric cell sensing based cell migration assay, we found that MDA-MB-231ALCAMexp cells showed marked reduction in migration compared with its control and parent cells. We have shown that inclusion of bone matrix proteins further reduced the migration speed of MDA-MB-231ALCAMexp cells.Conclusion. The present study provides cellular insight into the role of ALCAM in its involvement in bone metastasis of breast cancer. It is concluded that loss of ALCAM in breast cancer cells facilitates the invasive behaviour of breast cancer and highly levels of ALCAM in the cells have a suppressive role in the aggressive nature of breast cancer cells.1. Davies SR, et al, Oncol Rep., 2008, 19: 555-612. King JA et al, Breast Cancer Res., 2004, 6: R478-87

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6174.

Aberrant Expression of ARP2/3 in Breast Cancer and the Association with Disease Progression

Background: Increased motility is an important characteristics of neoplastic cells, a cell function mediated through actin polymerization. During this process, aside from creation of new branches and lengthening of pre-existing actin molecule, Actin-Related Proteins (ARP)- 2 and ARP-3 work as a complex promotes polymerization through production of new nuclei for actin polymerization. This regulation is orchestrated by other intracellular regulators including and WAVE and WASP proteins, which have been shown to be aberrant in breast cancer (1,2). In this study we determined the differential expression of ARP-2 and ARP-3 and correlated the expression with various prognostic factors.Methods: Expression of ARP-2 and ARP-3 was examined in a cohort of mammary tissues (n=33 normal breast tissue and n=127 primary breast tumor tissue samples). Transcript levels of ARP2 and ARP3 were then determined using quantitative real time PCR (Q-PCR) and protein levels were assessed using immunohistochemical (IHC) staining. Results were analyzed by Mann-Whitney U test.Results: Cytoplasmic staining for both ARP-2 and ARP-3 was noted along with strong epithelial staining as compared to stromal cells. Quantitative real time PCR (Q-PCR) data analysis showed lower expression of both ARP -2 & -3 in tumour tissue as compared to normal but without statistical significance. ARP-2 expression was significantly reduced in tumour samples from patients with poor prognosis (p=0.037) and patients who died of breast cancer (p=0.0265). Primary breast tumor tissue samples from patients classified as TNM stage 3 and 4 showed statistically significant lower expression of ARP-3 as compared to normal tissue (p= 0.019 and 0.020, respectively). ARP-3 expression was also significantly lower in patients who developed local recurrence of breast cancer (p=0.027). Using a Spearman correlation analysis, ARP-3 transcripts were find to be significantly correlated with the WAVE-2 transcript (r=0.42, p<0.01).Conclusions: Breast cancer shows aberrant expression of ARP-2 and ARP-3, a pattern linked to the prognosis of the patients. ARP-3 and WAVE-2 may have an intimate interplay in this association which warrants further investigation.References1. Fernando HS et al. Expression of the WASP verprolin-homologues (WAVE members) in human breast cancer. Oncology. 2007;73:376-3832. Martin TA, et al. N-WASP is a putative tumour suppressor in breast cancer cells, in vitro and in vivo, and is associated with clinical outcome in patients with breast cancer. Clin Exp Metastasis. 2008;25:97-108

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6169.

Prevalence and molecular diversity of Archaea in subgingival pockets of periodontitis patients

INTRODUCTION

The aim of this study was to investigate the prevalence and molecular diversity of Archaea in the subgingival crevices of patients with chronic periodontitis.

METHODS

Subgingival plaque was collected from 41 patients with chronic periodontitis and 15 healthy subjects. The prevalence of Archaea in those plaque samples was tested by polymerase chain reaction with two broad-range archaeal primer sets. Amplicons from eight Archaea-positive plaque samples were cloned and sequenced for molecular diversity analysis using one of these two primer sets and a novel third primer set.

RESULTS

Archaea were detected in the subgingival plaque of patients with chronic periodontitis at a prevalence of 70.7-73.2%, but were not detected in healthy subjects. Using one primer set, all sequences of the archaeal amplicons were identified as Methanobrevibacter oralis-like species. With another primer set, the amplicons were also found to be identical to the uncultured M. oralis-like species except one phylotype was found to belong to the class Thermoplasmata.

CONCLUSION

Archaea might be correlated with periodontal diseases. The diversity of Archaea associated with periodontitis was limited. Almost all sequenced amplicons fell into the genus Methanobrevibacter of the Euryarcheota phylum. M. oralis-like species was the predominant but non-exclusive archaeon in the subgingival dental plaque of patients with periodontitis.

Profile of volatile compounds in 11 brandies by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry

A headspace solid-phase microextraction (HS-SPME) method coupled with gas chromatography-mass spectrometry (GC-MS) was applied for the qualitative or semiquantitative characterization of brandy volatiles. SPME variables (SPME fiber, extraction temperature and time, and ethanol concentration) were optimized. A total of 144 compounds were from the brandies' volatiles, tentatively identified or identified by comparing mass spectra and retention indices of the standards or from literature. Of these, 57 are common to 11 brandies. They were mainly represented by esters and alcohols, such as 2-methyl propanol, 3-methyl butanol, 1-hexanol, ethyl octanoate, and ethyl decanoate, which were quantitatively determined. Chromatographic peaks were integrated using selective ion method (SIM) and the semiquantitative data analyzed using principal component analysis (PCA) and cluster analysis (CA) to study relationships between volatile composition and brandy. Eleven brandies were differentiated into 3 groups: 1 for Hennessy VSOP and XO samples, 1 for Changyu PEGASE VSOP and XO-1, 2, 3 samples, and the other for Changyu PEGASE brandy and VO, Taro brandy, Baiyang River brandy, and Wealth XO samples. The classification of groups is consistent with the brandy samples by variety and grade.

Minocycline attenuates oxidative/nitrosative stress and cerebral complications of acute liver failure in rats

In the present study, the effects of minocycline on progression of encephalopathy and brain edema in rats with acute liver failure (ALF) resulting from hepatic devascularization were studied in relation to the antioxidant action of the drug. ALF rats were sacrificed at precoma and coma stages of encephalopathy along with their appropriate sham-operated controls. Minocycline-treated ALF rats were sacrificed in parallel with comatose vehicle-treated ALF controls. Microglial activation was assessed using CD11b/c (OX-42) immunohistochemistry. Nitrite/nitrate levels in plasma and brain were measured using the Griess reaction. Expression of nitric oxide synthase (NOS) isoforms and heme oxygenase-1 (HO-1) were measured using real-time quantitative PCR and Western blot analysis. Increased nitrite/nitrate levels were observed in the plasma of ALF rats at coma stage of encephalopathy compared to sham-operated controls. Increased expression of HO-1 mRNA and protein was observed in the frontal cortex of ALF rats at both precoma and coma stages of encephalopathy. Significant increases in expression of endothelial (eNOS) and inducible (iNOS) isoforms of NOS mRNA and protein occurred only at coma stages of encephalopathy accompanied by increased brain nitrite/nitrate concentrations. As expected, minocycline attenuated microglial activation as confirmed by decreased OX-42 immunoreactivity, normalized nitrite/nitrate levels in brain and significantly attenuated HO-1, eNOS and iNOS expression. These results indicate that the beneficial effect of minocycline on the neurological complications of ALF is mediated, at least in part, by reduction of oxidative/nitrosative stress.

Predictive values of intratumoral microvascular density (MVD) in the patients (pts) with advanced NSCLC and metastatic colorectal cancer (mCRC) receiving chemotherapy plus bevacizumab

e14618

Background: The using of bevacizumab (VEGFR inhibitor) combined with chemotherapy represents a most noticeable recent advance in clinical oncology for significantly improving pts’ survival in several tumor types. There is an unmet need for seeking biomarker(s) to predict the treatment response of bevacizumab and identify the pts sensitive to the treatment. Our study was designed to investigate the predictive value of intratumoral MVD in NSCLC and mCRC pts treated with bevacizumab. Method: Sixteen NSCLC (stage IIIB/IV) and 15 mCRC pts who underwent chemotherapy (paclitaxel+carbo for NSCLC and IFL for CRC, respectively) combined with Bevacizumab were included into this study. The paraffin-embedded tumor samples (13/16 NSCLC and all CRC samples were collected from primary tumor) were sectioned and stained immunohistochemically for blood vessel markers (CD34 and CD31) to identify the characteristics of intratumoral vasculature. A computerized image analysis program was used to quantitatively calculate the intratumoral MVD (Yao et al., Clin Cancer Res 2007). Treatment response was evaluated by computed tomography scanning. Results: Two types of blood vessel, undifferentiated (CD31+/CD34-) and differentiated (CD34+), were identified. For the 16 NSCLC pts, a positive correlation was found between the largest tumor shrinkage percentage (evaluate in the primary tumors and metastases) and the total (CD31+) MVD as well as the undifferentiated (CD31+/CD34-) MVD, with Spearman's correlation coefficients equaled to 0.567 (p=0.022) and 0.576 (p=0.019), respectively. However, no significant correlation between tumor shrinkage and MVD was found in CRC pts, in which the treatment response was evaluated in metastatic lesions while the MVD was calculated in primary tumor. Conclusion: This exploratory analysis suggests higher total vessel and undifferentiated vessel MVD appeared to be predictive of bevacizumab treatment advantage for advance NSCLC pts.Our study also indicated that the MVD of primary lesions did not correlate with the treatment response of metastatic lesions in CRC pts. Further studies are needed to verify the predictive role of MVD in the treatment of bevacizumab in NSCLC.

[Table: see text]

The oligomeric subunit C rotor in the fo sector of ATP synthase: unresolved questions in our understanding of function

We have proposed a model for the oligomeric c-rotor of the F(o) sector of ATP synthase and its interaction with subunit a during H+-transport driven rotation. The model is based upon the solution structure of monomeric subunit c, determined by NMR, and an extensive series of cross-linking distance constraints between c subunits and between subunits c and a. To explain the complete set of cross-linking data, we have suggested that the second transmembrane helix rotates during its interaction with subunit a in the course of the H+-translocation cycle. The H+-transport coupled rotation of this helix is proposed to drive the stepwise movement of the c-oligomeric rotor. The model is testable and provides a useful framework for addressing questions raised by other experiments.

Estimating contrast transfer function and associated parameters by constrained non-linear optimization

The three-dimensional reconstruction of macromolecules from two-dimensional single-particle electron images requires determination and correction of the contrast transfer function (CTF) and envelope function. A computational algorithm based on constrained non-linear optimization is developed to estimate the essential parameters in the CTF and envelope function model simultaneously and automatically. The application of this estimation method is demonstrated with focal series images of amorphous carbon film as well as images of ice-embedded icosahedral virus particles suspended across holes.

Hypothermia attenuates oxidative/nitrosative stress, encephalopathy and brain edema in acute (ischemic) liver failure

Encephalopathy and brain edema are serious complications of acute liver failure (ALF). The precise pathophysiologic mechanisms responsible have not been fully elucidated but it has been suggested that oxidative/nitrosative stress is involved. In the present study we evaluated the role of oxidative/nitrosative stress in the pathogenesis of hepatic encephalopathy and brain edema in rats with ALF resulting from hepatic devascularization. We also studied the effect of hypothermia, a treatment previously shown to delay the progression of encephalopathy and the onset of brain edema, on ALF-induced oxidative stress. ALF rats were sacrificed at precoma and coma stages of encephalopathy along with their appropriate sham-operated controls. Hypothermic ALF rats were sacrificed in parallel with normothermic comatose ALF rats. Nitric oxide production in plasma and brain was assessed indirectly by measuring the level of its stable end products, nitrite/nitrate (NOx), using the Griess reagent. Expression of nitric oxide synthase (NOS) isoforms and heme oxygenase-1 (HO-1) were measured using real-time quantitative PCR, Western blot analysis and immunohistochemistry. Increased nitrite/nitrate levels were observed in the plasma and frontal cortex in ALF rats at coma stage of encephalopathy compared to sham-operated controls. Increased expression of HO-1 protein and mRNA was observed in the frontal cortex of ALF rats at both precoma and coma stages of encephalopathy. Significant increases in expression of endothelial and inducible NOS mRNA isoforms also occurred at precoma and coma stages of encephalopathy. Expression of the neuronal nitric oxide synthase isoform (nNOS) was not altered by ALF. Hypothermia normalized nitrite/nitrate levels in brain and significantly attenuated HO-1, eNOS and iNOS expression. These results suggest that, oxidative/nitrosative stress participates in the pathogenesis of brain edema and its complications in ALF and that the beneficial effect of hypothermia depends in part on its ability to inhibit oxidative/nitrosative stress-related mechanisms.

Overexpression of L1CAM accompanies acquired endocrine resistance and is associated with the development of an aggressive cell phenotype

Abstract #3028

Background: Acquired resistance to endocrine therapies is associated with a gain in aggressive features in vitro which may impact on tumour spread in vivo. To identify potential candidate molecules which may promote this adverse cell behaviour, we performed microarray analysis on MCF-7 cell models of fulvestrant resistance ('FasR' cells) applying a commercial algorithm for signalling network discovery. We have subsequently investigated the significance of overexpression of L1CAM, a cell-surface adhesion molecule implicated in a MAPK signalling network and recently associated with tumour metastasis, in FasR cells and in clinical tissue.
 Materials and Methods: A network analysis algorithm was applied to t-test significant Affymetrix gene lists derived from FasR vs. MCF-7 cells (Almac Diagnostics). Subsequent to revealing a prominent L1CAM network, L1CAM gene and protein expression were assessed using RT-PCR, Western blotting and immunofluorescence. Inhibition of L1CAM was achieved using siRNA transfection. Cell invasion and migration were measured by seeding onto Matrigel- or fibronectin-coated microporous membranes respectively. After 48 hours, invasive/migratory cells were fixed, stained and counted. Analysis of cell signalling molecules was determined using Western blotting with phospho-specific antibodies. Clinical significance of L1CAM expression was determined by analysis of L1CAM expression in tumour (n=101) vs. normal (n=23) breast tissue using Q-PCR.
 Results: Development of fulvestrant resistance in MCF7 cells was associated with ER loss and a gain in migratory and invasive capacity in vitro. L1CAM was overexpressed at both gene (p<0.05) and protein (p<0.01) level in FasR cells whereas little or no L1CAM was detectable in MCF7 cells confirming microarray findings. Network and ontological analysis predicted L1CAM lies upstream of an ERK2 network (26 genes; p<0.0001) impinging on transcription factors/regulators which may promote aggressive cell behaviour. In agreement, siRNA-mediated inhibition of L1CAM suppressed the activity of nuclear MAP kinase and reduced the intrinsic migratory and invasive nature of FasR cells in vitro. Preliminary analysis indicated L1CAM expression was inversely associated with ER status (p<0.01) and reduced overall survival (p=0.01).
 Conclusions: These data suggest that L1CAM overexpression associates with emergence of ER-negative fulvestrant resistance in breast cancer, where it may confer a highly motile and invasive phenotype. Additionally, our clinical studies suggest L1CAM may also contribute to inherently aggressive, ER-negative breast cancers. L1CAM signalling may thus provide a new therapeutic target to subvert such aggressive states in vivo.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3028.